Monday, March 9, 2020

VARIOUS TYPES OF SPINNING METHODS


 VARIOUS TYPE OF SPINNING METHODS:

Different types of spinning methods are given below:

Cover spun spinning

Self-twist spinning

Fascinated Spinning

Friction Spinning

Cover spun spinning:

The covers spun is both the name of a spinning system and a yarn. In this system staple roving gets drafted in a conventional manner. Now this drafted roving gets passed into a hollow vertical spindle. A filament yarn gets fed into the top of vertical hollow spindle. This filament being fed comes from outside rotating cylindrical spool . This spool  gets rotated at 20000 - 30000 RPM.

The rotating filament spindle causes the filament to wrap around the core of the staple to produce a wrapped yarn consisting of 80% to 95% staple.

Self-twist spinning:

In self-twist spinning, two parallel slivers get fed between two reciprocating rollers which form identical left hand or right hand twists in each of the slivers alternating down the length of the sliver. The resulting false-twisted yarns are then brought together, so that the right hand twist segment of one sliver is phased with the left hand twist of the other sliver. On relaxation, the slivers untwist over one another to form a stable yarn

Fascinated Spinning:

In fascinated spinning long staple sliver without twist is introduced into the Limited space and subjected to a torque jet operating at right angles to the flow of the sliver there by imparted a false twist to the sliver. As the sliver exits the torque jet, it rapidly untwists, and the outer fibres tend to break away from the sliver and get wrapped around the inner sliver to give a strong yarn consisting of mostly parallel fibres with some fibres tightly twisted around the outside.

Friction Spinning:

The basic principle of friction spinning is that it is an opening system, it is a variation of the open-end spinning system and often referred to as the DREF system. The fibers are carried with an air flow forward, to the collecting area between the two friction surfaces. The friction spinning like Air-Jet spinning is limited in practice by the yarn quality. Finer count yarn produced in friction spinning than ring or Rotor spinning with comparatively production level. In this system, one or more slivers are fed onto a rapidly rotating card drum which opens the sliver to form single fibers. The separated single fibers are blown from the card drum by a stream of air onto the junction of two parallel perforated drums turning in the same direction. The rotating perforated drums under suction cause the fibers to be compressed and twist around one another to form a uniform yarn which is continuously wound onto a spool. The resultant yarns are bulky and have properties similar to woolen yarns.

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